Continuous-twyer furnace.



G. W. MUNSON'.

CONTINUOUS TWYER FUBNAOE.

APPLIOATIoN FILED man1, ma.

972,126. Patented oem, 1910. A

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UNITED STATES PATENT OFFICE.

CORYDON W. MUNSON, OF TOLEDO, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS, TOMARY OWEN MUNSON.

CONTINUOUS-TWYER FURNACE.

Specification of Letters Patent.

Application filed March 7, 1908.

Patented Oct. 4, 1910. seran No. 419,696.

To aZZ whom t may concern:

Be it known that I, CoRYDoN lV. MUNsoN, a citizen of the United. States,residing at Toledo, in the county of Lucas and State of Ohio, haveinvented certain new and useful Improvements in Continuous-'lwyerFurnaces, of which the following is a specification.

This invention relates to apparatus for the application of theprinciples embodied in modern practice of smelting pyrites or sulfidores or artificial sulfites carrying gold, silver, copper or other metalvalues, the purpose and object being to utilize the fuel elements ofsulfur and iron in the ores to furnish the heat to smelt themselves withthe use of but little or no extraneous fuel.

The usual method of smelting practice is a reducing or melting down ofthe ores; but it is well known that the hot-blast smelting of sulfidores is an oxidizing process, where a large volume of heated air isdriven into the ore body in the furnace under pressure, producing` arapid oxidation of the sulfur in the ores, and an intense heat isdeveloped and maintained by releasing the sulfurous gases as the oresare melted, these gases combining with the oxygen of the heatedairblast, and are driven into the ore body.

The usual blast furnace practice is to drive the air-blast into the orebody in the furnace through separate round openings or twyers, resultingin an unequal oxidation. The blast penetrating the ore mass in thefusing Zone at separate and individual locations tends to produceaccretions at and around the twyer-openings, which interfere with theuniform distribution of the air blast through the ore mass, thuslessening the efficiency of the furnace. The ore body in the furnacealso covers these twyer openings, obstructing the free passage of airinto the ore mass, and causing uneven and variable results at differentpoints because of the uneven delivery of the air, caused by suchobstructions.

The object of my present invention is to provide an improved apparatusfor carrying out the proce-ss claimed in my Patent 846,498, grantedMarch 12, 1907, the said improved apparatus comprising a furnace whichdisn penses entirely with separate twyers, and preferably formed with awidened hearth.

To these ends, my invention consists in the construction and combinationof parts substantially as hereinafter described and claimed.

Of the accompanying drawings :-Figure l is a vertical section of afurnace embodying` my improvements. Figs. 2, 3 and 4 are similar views,illustrating modifications hereinafter described.

Similar reference characters indicate the same or similar parts on allof the figures of the drawings.

Referring first to Fig. l, a suitably supported hearth is represented at20, its wall 21 being formed with a discharge-hole 22, through which themolten product passes to the spout 23 for tapping it off. This heal-tlvsection may be constructed in any wellknown or preferred manner. Itsshape in plan may be round or elongated. The vertical portion 2l isshown in this figure as hollow to form a water jacket, or it may besolid as indicated in Fig. 4.

The upper portion or furnace wall proper is indicated at 24 said upperportion being supported in position so as to be entirely separated fromthe lower portion or hearth wall 2l by an annular space or passage way25 for the air for the blast. A suitably constructed hot air box 26surrounds the furnace and is in open communication with the annularspace or passage way 25, the supply of hot air at the proper temperaturebeing obtained by means of any suitable apparatus and supplied underpressure to the box 26 through the pipe 27.

Then the wall sections 21 and 24 are made hollow, a suitable supply ofwater for coo-ling purposes is furnished thereto through pipes 28 and29. The upper portion or furnace wall proper 24 may be supported in itsposition relatively to the hearth wall section 2l by means of aninclined top 30 of the box 26, the upper edge of said top 30 beingsecured in any suitable way to the outside of the section 24. Supportingbraces 31 may also be employed, or they may be omitted.

The hearth is greater or wider in diameter than the lower edge of thewall section 24. Therefore, when ore is repeatedly supplied in anysuitable way through the upper portion of the furnace so as to form andmaintain a low charge with inclined sides from the base upward, thenatural incline of fall of the sides of the pile or heap of ore belowthe lower edge of the upper section 24 will be such that the loose oreor the molten mass cannot fall or How into the annular space or airpassage way 25. Below said annular space or passageway, when the furnaceis filled with ore, there is a confined circular air-space or annularchamber which circles the entire body of ore on the furnace hearth sothat the hot air supplied under pressure through said annular passageway is distributed evenly and against the exposed surface of the orebody instead of being driven into the ore at separate locations as isthe case when a series of twyers are employed. Therefore the airpenetrates the ore uniformly at all points and under uniform pressureover the entire surface below the lower edge of the furnace section 2t.And the hot blast is confined in the space into which it is drivenbecause it is not free to pass upward over the surface of the ore pile.

It is well known that with twyer openings through the walls of blastfurnaces as usually constructed, the inner ends or openings of thetwyers are covered by the ore and free passage of air through the twyersis more or less obstructed, thus lessening the efliciency and capacityof the furnace. It also involves much trouble and annoyance to keep thetwyer openings free. By my construction the annular opening is kept freefrom any obstruction by the ore in the furnace, because the relation ofthe bottom of the upper section 24 of the furnace to the top of thewidened hearth section 21 is such as to make impossible the obstructionof the continuous twyer opening between the two sections by ore fallinginto said opening.

In Fig. 2 the structure is substantially the same, but in said figure Ihave shown the upper portion of the furnace as closed by a masonry top32, said top supporting a hopper 33 having a cover 34 which is adaptedto be tightly closed. With this structure the ore may be suppliedthrough the hopper 33, while the products of combustion escape through asuitable outlet or stack 35. In said Fig. 2 I also show the top of theair boX 26 as having a flange 36 on which rests the ring 37 which issecured around the furnace section 24. In said ligure I also show thetop of the hearth section 2l as inwardly and downwardly inclined and thelower edge of the furnace section 24 as rounded, this being a form whichmay be preferred for some purposes in that the annular air blast isdirected squarely against the inclined surface of the lower portion ofthe ore charge. Fig. 3 shows a structure similar to Fig. 1

but having the sides of the furnace section 24 tapering or convergingdownwardly instead of having parallel walls.

In Fig. 4lthe structure is substantially the same as in Fig. 2 but thesides of the hearth section or wall converge instead of bein@ parallelor vertical as indicated at 210, said section or wall being formed solidof any suitable material.

It will. be observed that in each form of furnace illustrated individualtwyers are absolutely dispensed with, but an opening is formed which isso protected that it will not become clogged either by the loose orecovering or falling into or over said opening, or the molten mass risingabove its normal height, the result being that the pressure of air isabsolutely uniform over all portions of the base of the heap or pile ofore, because the passage of air through the continuous twyer is alwaysfree from obstruction.

It is to be understood, of course, that in cross section the furnace maybe either circular or of other shape. l

It is to be understood that I do not limit in vself to the precisedetails of construction described and illust 1ated, since I mayvariously modify the same within the limits of mechanical skill.

Having now described my invention what I claim is 1. A smelting furnacecomprising a hearth and having side walls in two entirely separatedportions with an annular space between them, and means for forcing anair blast through said annular space in a downward direction uponsurface portions of a heap of ore on said hearth.

2. A smelting furnace with a top or upper section and a hearth or lowersection of greater diameter, the two sections sepa.- rated by a space,and an air box permanently attached to both top and bottom sections, andinclosing or covering the opening or space between said sections theplane of said space being above the plane of the base of a heap of oreon said hearth and adapted to direct the air in a downward direction onsaid base.

In testimony whereof I aiix my signature, in presence of two witnesses.

CORYDON W. MUNSN.

IVitnesses BLANCHE M. VAN ARSDALE, ALONZO G. DUER.

